Current continuously variable transmission (CVT) technologies use friction-drive to control the transfer of power. Friction-drive systems can not handle high torque efficiently due to slippage. Friction-drive systems use a belt and pulley or a disk and rubber wheel to transmit torque through the drive train. The belts or wheels slip. Friction is added to reduce slippage which in turn adds drag and cuts down on efficiency. Car designers use multi-speed transmission, some up to 8 speeds, to try to best match the engines efficiency range with the typical driving speeds. All engines, gas, diesel, electric etc. operate most efficiently at a particular rpm range. Current CVT systems are not used in higher torque applications because the efficiency of having an engine run at its most efficient rpm range is negated by the inefficiency of torque transfer.
In theory a transmission moves in a continuous motion. To date the actual operation of transmissions has been less than continuous motion. In manual transmissions shifting gears requires passing through a neutral position and perhaps disengaging a clutch which causes the motor to rotate with less load or even without load. This interrupts and reduces the amount of work being accomplished and wastes power or energy. Automatic transmissions are more efficient because the delays caused by human abilities to shift were inconsistent, but with automatic transmissions the shifting still occurs. Current continuously variable transmission or CVT systems, although an improvement over automatic transmissions, accomplish the variable transitions by transferring power using friction from two variable diameter objects thereby varying the ratio with power losses due to slippage.